The inventors have recognized several problems in the field of communication systems and network environments. In a long term evolution (LTE) network environment, there may be two mechanisms for providing voice services. One mechanism may be through the support of voice over LTE (VoLTE), and the other may be through the circuit switch fall back (CSFB) mechanism. A user equipment (UE) may be one of a voice centric device and a data centric device. In the LTE network environment, the mechanism to support voice services includes using over the top (OTT) applications which are fully supported as voice calling applications in LTE networks or rich communication suite/services (RCS) application which are used as a voice calling application. With the evolution of user equipment, there has been a proliferation of CSFB supporting devices, but not the VoLTE (Voice over LTE) supporting devices. Therefore, the LTE network that can support only VoLTE and RCS framework may not be advantageous as the LTE network is not capable of supporting the current CSFB supporting devices for providing calling based services in the LTE network.
In an LTE network architecture, the CSFB mechanism in EPC (Enhanced Packet Core) enables provisioning of the voice and traditional circuit switch (CS)-domain services (e.g. CS UDI video/SMS/LCS/USSD). Hence, to provide these services, the LTE network may reuse the CS infrastructure while the UE is served by E UTRAN (evolved universal terrestrial access network). A CSFB supporting user equipment connected to E UTRAN may use GERAN (GSM EDGE radio access network) or UTRAN to connect to the CS domain. However, this function may be only available in case E UTRAN coverage is overlapped by either the GERAN coverage or the UTRAN coverage.
Further, the voice over LTE (VoLTE) scheme for providing voice over the LTE network may utilize IMS (IP Multimedia Subsystem) for enabling the VoLTE to be a part of the rich communication services. However, this is only an option chosen by the GSMA (GSM Association) for use on LTE and is the standardized method for providing services such as SMS, voice over LTE and video call over LTE.
The CSFB and the IMS based services can co-exist in a same operator network. However, to support CS fallback functionality is not routine, and requires all participating elements such as the user equipment, mobility management entity (MME), mobile switching center (MSC) and E-UTRAN to support additional functionalities such as maintaining quality of service (QoS), serving gateway (SGW) and program dependency graph (PDG) using the policy and charging rules function (PCRF).
Furthermore, with the LTE only network and a limited LTE device with CSFB capability having no VoLTE functionality, there arises a situation where the device may not be able to latch to the network since the LTE network does not allow CS services. Accordingly, as per the 3GPP standard, for example, if the user equipment is in CS/PS mode 1, the device may try to move and latch to the 2G/3G network having voice calling functionality. However, for the LTE only network, the situation may be raised to keep the user equipment with the LTE network for all the high-speed Internet services.
Furthermore, both the CSFB and the VoLTE devices by default may be voice centric in nature. Therefore, in one scenario, if the LTE network does not support CSFB mechanism, then the CFSB capable devices may not attach to such LTE only network at all. This can be an issue in networks that support only data services in LTE networks.
Accordingly, there is a need for systems and methods for providing services such as voice calling through an LTE only network to the legacy devices supporting CSFB mechanism.
Certain embodiments of the present disclosure solve this need, and may provide a mechanism that modifies the specifications of user equipment to allow latching of the user equipment onto the LTE only network for high-speed Internet services as well as services such as voice calling via OTT (Over-the-top) or RCS (Rich Communication Services) based applications.